Harbin closed with 73 and finished at 8-over 296.
In a sudden-death playoff, former Ivy League star Peter Williamson ran in a 25-foot birdie on the third hole to beat Alabama’s Bobby Wyatt, the world No. 1 ranked amateur.
They finished at 12-under 276.
“What a day,” Williamson said. “Our threesome all shot 67 – 15-under-par in the final round. It was a frantic pace. Winning a tournament this big against the No. 1 player feels good. I’ll have to digest it.”
As champion, Williamson earns the option of playing in the PGA Tour’s Arnold Palmer Invitational in March in Orlando, Fla., provided he remains an amateur at that time.